Shear cut perforator



9, 1966 E. D. NYSTRAND 3,264,921

SHEAR CUT PERFORATOR Filed March 4, 1965 2 Sheets-Sheet 1 gag/mg aLaramie/"w 9, 1966 E. D. NYSTRAND 3,264,921

SHEAR CUT PERFORATOR Filed March 4, 1965 2 Sheets-Sheet 2 United StatesPatent Office 3,264,921 Patented August 9, 1966 3,264,921 SHEAR CUTPERFORATOR Ernst Daniel Nystrand, Green Bay, Wis., assignor to PaperConverting Machine Company, Inc., Green Bay, Wis, a corporation ofWisconsin Filed Mar. 4, 1965, Ser. No. 437,226 Claims. (Cl. 83342) Thisinvention relates to a shear out perforator, and, more particularly, toapparatus for transversely perforating continuous webs of toilet tissue,and the like.

This invention is an improvement on U.S. Patent No. 2,870,840, issuedJanuary 27, 1959, to Edwin M. Kwitek. It is also an improvement on U.S.Patent No. 2,986,058, issued May 30, 1961, to Orrin Besserdich.

Both of the abovementioned patents have to do with a perforating head orattachment for a continuous rewinder. A rewinder is commonly employed inthe production of retail-sized rolls of toilet tissue and toweling. Intoilet tissue, for example, the web is transversely perforated on 4%."centers and this is performed during the time a web is being rewoundfrom a parent or jumbosized roll into the retail-sized rolls commonlypurchased.

Web winding apparatus of the character to which this invention isapplicable can be seen in U.S. Patent No. 2,769,600, issued November 6,1956, to Edwin M. IQwitek and Ernst Daniel Nystr-and. Furtherparticulars of the rewinder can be seen in the co-owned, copendingapplication of Ernst Daniel Nystrand, John 1. Bradley and Harvey J.Spencer, Serial No. 223,994, filed September 19, 1962, now Patent No.3,179,348.

This invention is particularly concerned with the cutting bladesemployed in the perforating attachment of the rewinder, and a generalobject of the invention is to provide a unique arrangement ofperforating blades to facilitate perforating during rewinding.

Other objects and advantages of the invention may be seen in the detailsof construction and operation set down in this specification.

The invention is explained in conjunction with an illustrativeembodiment in the acompanying drawing, in Which FIG. 1 is a fragmentarysectional view of a perforating attachment;

FIG. 2 is a perspective view of the attachment of FIG. 1;

FIG. 3 is an enlarged fragmentary sectional view of the central portionof FIG. 1; and

FIG. 4 is a view similar to FIG. 2 but showing a modified form of theinvention.

In the illustration given, and with particular reference to FIGS. 1 and2, the numeral designates a perforating bedroll of the character seen inthe above-mentioned Kwitek Patent No. 2,870,840. The bedroll 10 isjournaled for rotation within side frames 11. A gear train 12 may beemployed for rotating the bedroll 10 in synchronism with an advancingweb designated W.

The web W is seen to be traveling with and on a portion of the surfaceof the bedroll 10, being in partial Wrapping engagement therewith. Forthis purpose, the web is fed under an idler roll 13 and partially aroundan intermediate roll (not shown). Also not shown but well known to thoseskilled in the art is the turret portion of the rewinder which receivesthe web W following its passage around the intermediate roll.

The bedroll 10 is seen to be equipped with a plurality of longitudinallyor axially-extending recesses 15, one of which can be seen in enlargedscale in FIG. 3. Each recess carries a flexible blade 16 in the mannershown in greater detail in the above-mentioned Kwitek Patent No.2,870,840. In one aspect of the invention, the bedroll 10 and themounting of the flexible blades 16 may follow the teaching of theabove-mentioned Kwitek patent. In the patent, the recess is equippedwith a rigid bearing surface at 17 supporting the lower or inner edgeportion of the flexible blade 16. The blade 16 is clamped against therigid bearing surface 17 by means of a clamp member 18, and interposedbetween the clamp member 18 and the blade 17 is a resilient strip 19.The recess 15 is equipped with an additional recess 20 which permits theouter or upper edge portion of the blade 16 to flex inwardly duringcutting and when the same engages an anvil blade 21.

The anvil blade 21 is mounted in a fashion analogous to the roll blade16. For this purpose, an anvil bladesupporting member 22 is provided andwhich is equipped with a rigid bearing surface as at 23. The inner endportion of the blade 21 is supported on the surface 23 and maintainedthereon by a clamping element 24.

For the purpose of receiving the blade 21 and the clamping element 24,the member 22 is slotted as at 25 and threadedly bored to receive asetscrew 26. Thus, the blade 21 is securely fixed in place. The member22 is in turn secured to a crossbeam 27 by means of studs 28 (see alsoFIG. 2). In practice, two studs 28, each equipped with suitable nuts 29,are employed for each bladesupporting member 22. The members 22 arefirmly clamped to the beam 27 by means of the co-action of the stud 28,the bolt 29, and a spring-like washer 30. The block-like member 22 isequipped with a through bore 31 for the receipt of the stud 28, and itwill be seen that the bore 31 is larger than the stud 28 to permitvertical ad- 'justment of the member 22 under the influence of adjustingscrews 32 and 33. Each member 22 is adjusted by three screws, the screws32 hearing against the upper surface of the member 22, While theintermediate screw 33 is threadedly received within the member 22.

As in the case of the flexing blade 16 provided on the bedroll 10, theflexing blade 21 supported in the member 22 has associated therewith asupplemental recess 34. This permits limited flexing of the outer edgeportions of the flexing blade 21 when it engages the roll blade 16. Aswear occurs on the blades, the interference or overlap between theblades 16 and 21 must be adjusted, and this is achieved throughrepositioning of the screws 32 and 33. As the flexing blades wear, thecorner cutting edges become slightly beveled so that increasedinterference is required. A normal interference may be of the orderofabout 0.008" for webs such as retail toilet tissue and toweling.

Reference to FIG. 2 reveals that a plurality of bladesupporting elements22 are provided across the width of the machine. Advantageously, theelements 22 are arranged in a spiral fashion relative to the roll blades16 so as to develop a progressive point contact between the blades 16and 21. Thus, each anvil blade 21 is offset relative to adjacent anvilblades, and the composite series of chords defined by the anvil bladesdefine a saw or loose spiral. Each individual anvil blade 21 is arrangedat an angle to the axis of the bedroll 10 of the order of 2 /2 to 5 sothat the above-mentioned progressive point contact between the blades isachieved. It will be appreciated that under some circumstances such aswider machines, the anvil blades 21 may be arranged in the form ofseveral spirals so that at any given instant there are several points ofcontact between individual roll and anvil blades across the width of themachine.

For ease of installing replacement blades, the rigid bearing surface 17may terminate in a shoulder 35 which facilitates the replacement of theblades 16. Also, the recess 15 may be equipped with a back-up block asat 36 suitably mounted on the bedroll 10 by means of a bolt 37 so as tosupport the outermost portion of the blade 16 against excessive flexure.

Still further, it may be advantageous in some instances to provide forselective movement of the members 22 in emergency, i.e., abnormalconditions. For example, at times the fast-traveling web may developwads or may tear and begin to wrap the bedroll 10. In such case, therotating bedroll is stopped and the waste tissue re moved. This isfacilitated by moving the members 22 away from the bedroll 10, and thismay take the form of the hinging or pivoting described in theabove-mentioned Kwitek and Besserdich patents. Such member movement canalso be advantageous during start-up as when threading the machine.

Optimally, the flexible blades 16 and 21 have a thickness of the orderof 0.025" to about 0.50", with the supplemental recesses 20 and 28 beingof the same order of magnitude, i.e., from about 0.010" to 0.05 measuredin a direction perpendicular to the confronting face of the unfiexedassociated blade. 21 have an unsupported width of about "V whichadvantageously may be half of the overall width. The length of eachblade is conveniently set at 4 /2", corresponding to the width of anultimately developed retail-sized roll. Over such width, the roll blade16 may be notched to provide bonds between perforation slits in thefashion shown in the above-mentioned Kwitek patent.

In FIG. 1, a first construction line 36 has been drawn from the centerof the bedroll to the inner edge of the roll blade 16, i.e., the edgeabutting the shoulder 35. This is seen to be forward, relative to thedirection of rotation of a radial line 37 drawn from the center of thebedroll to the cutting edge of the bedroll blade 16. In this connection,it will be appreciated that both edges may be notched so as to permitrepositioning of the blade 16 in four different positions and therebyeffectively extend the working life. In like fashion, the anvil flexingblade 21 may be repositioned because of the four cutting edges providedthereon.

Relative to the anvil flexing blade 21, it will be seen that its inneredge, i.e., the edge abutting the shoulder 38, is also forward of theouter cutting edge. Alternatively, this can be reversed in the fashionseen in FIG. 4 where a radial line drawn to the inner edge of the blade21 lies rearwardly of the radial line drawn from the center of thebedroll 10 to the outer or cutting edge of the flexing blade 21. Ineither event, it will be seen the anvil blade 21 forms an obtuse anglewith a radial line drawn to the cutting edge thereof. In contrast, theflexible blade 16 forms an acute angle with the radial line 37 drawn toits cutting edge. This acute angle advantageously is of the order ofabout 25 to about 65, while the obtuse angle formed by the radial lineand the anvil blade 21 is of the order of about 115 to about 155.

In operation, the bedroll 10 may be equipped with a plurality ofrecesses 15 and therefore a plurality of rows of flexing blades 16. Eachrow is arranged parallel to the axis of the bedroll 10 and thecircumferential spacing of the rows develops the distance betweentransverse perforations in the web 12. The web 12 may be advanced at alineal speed of the order of 1000-2000 feet per minute, and during suchoperation the blades 16 and 21 yield slightly inwardly to compensate forthe interference or overlap, which may be of the order of 0.008" toabout 0.012". It will be appreciated that at least initially greaterinterference occurs at the center of the aligned blades 16 and 21, sincethe blades 21 are arranged on the chord of a spiral, as contrasted to atrue spiral. Thus, there may be greater interference in the centers ofthe blades than at the edges. During operation, the inward flexing ofthe roll blades 16 results in a slight release of the tension on the webW, whereby the tendency of the web W to shred or burst is minimized. Theslight inward, i.e., upward, yielding of the anvil blade 21 during thesame en- Normally, the blades 16 and gagement partially relieves thedeforming stress on the roll blade 16. whereby the useful life may beprolonged.

In FIG. 3, it is seen that the anvil blade 21 is essentially forwardlyand upwardly inclined (relative to the direction of web travel). Thisprovides an advantageous arrangement in that the 'bedroll 10 can bebacked up. In certain emergency conditionsas where an operator is caughtin the machine-it can be remedied quickly by backing the machine upslightly and arrangement of the anvil blade 21 as depicted in FIG. 3permits this without overstressing the blades 16 and 21.

The showing in FIG. 4 differs essentially from that of FIG. 3 in thearrangement of the anvil blade 121. In FIG. 4, the anvil blade 121 isseen to be rearwardly and upwardly inclined relative to the direction oftravel of the bedroll 110. However, the same cooperative action existsbetween the anvil blade 121 and the bedroll blades 116. The arrangementin FIG. 4 may be used in some cases where there is a tendency of the webto catch or hang up on the anvil blade 21 of FIG. 3. Normally, however,this does not occur with carefully prepared paper. In FIG. 4, the rollblade is seen to be secured in place by the clamp 118, and the anvilblade 121 is suitably clamped along its inner edge portion by means of aclamping member 124 mounted within the slot 125 of the anvilblade-carrying member 122.

While in the foregoing specification a detailed description of anembodiment of the invention has been set down for the purpose ofexplanation and illustration, many variations in the details hereingiven may be made by those skilled in the art without departing from thespirit and scope of the claims.

I claim:

1. In web perforating apparatus, a frame, a cutting bedroll mounted forrotation in said frame, means for rotating said roll, means for feedinga web on said roll in partial wrapping engagement therewith, said rollhaving an axially-extending recess in the surface thereof and a rigidbearing surface within said recess, a resilient blade having its inneredge portion rigidly supported on said bearing surface and having aninclined, outwardlyextending free portion provided with a cutting edge,said roll being provided with a further recess about saidoutwardly-extending free blade portion for relieving the same forflexing, the inclination of said blade being such that it forms with aradial line drawn from its cutting edge to the roll center an acuteangle, a radial line drawn to said inner edge being forward of thefirst-mentioned radial line relative to the direction of roll rotation,an anvil blade-supporting member mounted on said frame adjacent saidroll adapted to support an anvil blade for contact with said roll blade,said member being equipped with a rigid bearing surface, a resilientanvil blade having its inner edge portion supported on said memberbearing surface and having an inclined, outwardly-extending free portionprovided with a cutting edge, said member being provided with a recessabout said anvil block outwardlyextending free portions for relievingthe same for flexing, the inclination of said anvil blade being suchthat it forms with a radial line drawn from its cutting edge to the rollcenter an obtuse angle, said anvil blade inner edge portion beingrigidly supported on said member bearing surface when said blades areperforating webs sized within the limits of proper adjustment of saidblades, said anvil blade cutting edge being radially inward of the pathof travel of the roll blade cutting edge to interfere with the same,said anvil blade being arranged with its cutting edge at an angle to thecutting edge of said roll blade as the cutting edges of said blades arebrought into engagement during the rotation of said roll whereby aprogressive point cutting is developed, one of said blades beingequipped with a plurality of notches in its cutting edge to provideperforation bonds in said web, said member being fixed against rotationwhen said blades are perforating webs sized within the limits of properadjustment of said blades.

2. The structure of claim 1 in which said roll is equipped with aplurality of identical recesses equally circumferentially spaced, eachrecess being equipped with a further recess and a resilient blade.

3. The structure of claim 1 in which the thickness of each blade is ofthe order of about 0.025 to about 0.050" and each flexing recess has adepth measured in a direction perpendicular to its associated blade ofthe order of about 0.010" to about 0.050".

4. The structure of claim 1 in which means are operatively associatedwith said frame for moving said anvil blade out of interference withsaid roll blade when webs 5 angle is in the range of about 115 to about155.

No references cited.

ANDREW R. IUHASZ, Primary Examiner.

WILLIAM w. DYER, 1a., Examiner.

L. B. TAYLOR, Assistant Examiner.

1. IN WEB PERFORATING APPARATUS, A FRAME, A CUTTING BEDROLL MOUNTED FORROTATION IN SAID FRAME, MEANS FOR ROTATING SAID ROLL, MEANS FOR FEEDINGA WEB ON SAID ROLL IN PARTIAL WRAPPING ENGAGEMENT THEREWITH, SAID ROLLHAVING AN AXIALLY-EXTENDING RECESS IN THE SURFACE THEREOF AND A RIGIDBEARING SURFACE WITHIN SAID RECESS, A RESILIENT BLADE HAVING ITS INNEREDGE PORTION RIGIDLY SUPPORTED ON SAID BEARING SURFACE AND HAVING ANINCLINED, OUTWARDLYEXTENDING FREE PORTION PROVIDED WITH A CUTTING EDGE,SAID ROLL BEING PROVIDED WITH A FURTHER RECESS ABOUT SAIDOUTWARDLY-EXTENDING FREE BLADE PORTION FOR RELIEVING THE SAME FORFLEXING, THE INCLINATION OF SAID BLADE BEING SUCH THAT IT FORMS WITH ARADIAL LINE DRAWN FROM ITS CUTTING EDGE TO THE ROLL CENTER AN ACUTEANGLE, A RADIAL LINE DRAWN TO SAID INNER EDGE BEING FORWARD OF THEFIRST-MENTIONED RADIAL LINE RELATIVE TO THE DIRECTION OF ROLL ROTATION,AN ANVIL BLADE-SUPPORTING MEMBER MOUNTED ON SAID FRAME ADJACENT SAIDROLL ADAPTED TO SUPPORT AN ANVIL BLADE FOR CONTACT WITH SAID ROLL BLADE,SAID MEMBER BEING EQUIPPED WITH A RIGID BEARING SURFACE, A RESILIENTANVIL BLADE HAVING ITS INNER EDGE PORTION SUPPORTED ON SAID MEMBERBEARING SURFACE AND HAVING AN INCLINED, OUTWARDLY-EXTENDING FREE PORTIONPROVIDED WITH A CUTTING EDGE, SAID MEMBER BEING PROVIDED WITH A RECESSABOUT SAID ANVIL BLOCK OUTWARDLYEXTENDING FREE PORTIONS FOR RELIEVINGTHE SAME FOR FLEXING, THE INCLINATION OF SAID ANVIL BLADE BEING SUCHTAHT IT FORMS WITH A RADIAL LINE DRAWN FROM ITS CUTTING EDGE TO THE ROLLCENTER AN OBTUSE ANGLE, SAID ANVIL BLADE INNER EDGE PORTION BEINGRIGIDLY SUPPORTED ON SAID MEMBER BEARING SURFACE WHEN SAID BLADES AREPERFORATING WEBS SIZED WITHIN THE LIMITS OF PROPER ADJUSTMENT OF SAIDBLADES, SAID ANVIL BLADE CUTTING EDGE BEING RADIALLY INWARD OF THE PATHOF TRAVEL OF THE ROLL BLADE CUTTING EDGE TO INTERFERE WITH THE SAME,SAID ANVIL BLADE BEING ARRANGED WITH ITS CUTTING EDGE AT AN ANGLE TO THECUTTING EDGE OF SAID ROLL BLADE AS THE CUTTING EDGES OF SAID BLADES AREBROUGHT INTO ENGAGEMENT DURING THE ROTATION OF SAID ROLL WHEREBY APROGRESSIVE POINT CUTTING IS DEVELOPED, ONE OF SAID BLADES BEINGEQUIPPED WITH A PLURALITY OF NOTCHES IN ITS CUTTING EDGE TO PROVIDEPERFORATION BONDS IN SAID WEB, SAID MEMBER BEING FIXED AGAINST ROTATIONWHEN SAID BLADES ARE PERFORATING WEBS SIZED WITHIN THE LIMITS OF PROPERADJUSTMENT OF SAID BLADES.